#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define R read()
#define fi first
#define se second
using namespace std;
inline int read(){
	int x=0; char c=0;
	while(c<'0'||c>'9') c=getchar();
	while(c>='0'&&c<='9') x=x*10+c-'0',c=getchar();
	return x;
}
const int inf=0x3f3f3f3f,N=100005;
const ll INF=0x3f3f3f3f3f3f3f3f,M=1000000007;
int T,n,m,v;
pair<int,int> p[N];
ll ans;
ll power(ll x,int y){
	ll res=1;
	while(y){
		if(y&1) res*=x,res%=M;
		x*=x,x%=M,y>>=1;
	}
	return res;
}
int main(){
	freopen("assign.in","r",stdin);
	freopen("assign.out","w",stdout);
	T=R;
	while(T--){
		n=R,m=R,v=R,ans=1;
		for(int i=1;i<=m;i++) p[i]={R,R};
		sort(p+1,p+m+1);
		m=unique(p+1,p+m+1)-p-1;
		for(int i=2;i<=m;i++){
			if(p[i].fi==p[i-1].fi){
				puts("0");
				goto out;
			}
			ans*=power(v,2*(p[i].fi-p[i-1].fi))-power(v,p[i].fi-p[i-1].fi-1)*(v-1)%M+M;
			ans%=M;
		}
		ans*=power(v,2*(p[1].fi-1)),ans%=M;
		ans*=power(v,2*(n-p[m].fi)),ans%=M;
		printf("%lld\n",ans);
		out:;
	}
	return 0;
}